Nickel alloy and process of making the same



Patented @ept. 29, M36

NICKEL ALLOY AND 'llHlE Hugh S. Cooper, Cleveland,

PRU CE S S F SAME Dhio, assignor, by

mesne assignments, to Union Carbide and Carhon Corporation,

No Drawing.

Serial No.

6 @laims.

relates to alloys of nickel, bariand to a new process for 10 'one or more other metals are present to act as coupling or homogenizing agents. Nickel-barium alloys produced commercially by known processes seldom contain more than about 0.05% barium, and even under carefully controlled laboratory conditions it is diflicult to attain a barium content as high as 0.30%. Microscopic examination of these products reveals the fact that a great part, if not all, of the barium is distributed between the grains of the nickel, and is not truly alloyed with, or dissolved in, the nickel.

Most attempts to alloy barium with nickel have employed the commonly accepted method of alloying metals of diflerent melting points, namely, to melt the higher melting metal, in this case nickel, and to add the lower melting metal, in this case the barium or strontium. Applied to nickel, barium, strontium alloys, this method fails completely, probably due in great part to vaporization of the volatile alkaline earth metal at the melting point of nickel.

It has been proposed to. make barium-nickel alloys by mixing powdered barium with finely divided nickel, compressing the mixture, and heating the compressed slugs or bars under pressure of barium vapor. This process must be conducted in its'entirety out of contact with air, in order to prevent the inclusion of large amounts of oxides. Even under the most carefully controlled conditions it is practically impossible to prevent the 40 formation oi these oxides and nitrides, because of the extreme chemical activity of finely divided barium and does not yield homogeneous true tions of nickel and barium.

It has also been proposed to mix barium azide, a highly explosive compound, with powdered nickel, to compress the mixture, and to decompose the nitride. The process is inherently very dangerous to use, and does not yield true alloys. The present invention provides a simple process for making homogeneous alloys of nickel, barium, and strontium, containing any and all desired proportions oi these It is found that although strontium or barium will not dissolve to a marked extent in molten alloys or solustrontium. Moreover, the process a corporation oi New York Application July 7, 1933,

nickel, nickel will readily dissolve in superheated molten barium or strontium, yielding an alloy containing up to approximately 35% nickel, and that alloys so obtained and containing about 5% to about 35% nickel are readily dissolved by molv5 ten nickel.

The process comprises melting barium or strontium, or a mixture of the two, in helium or other inert gas, or in vacuo, superheating the melt, preferably to ap roximately 1000 solid or melted nickel;

about 35% nickel.

Examples of alloys which have been made ac- 20 cording to the invention include nickel-barium alloys containing respectively 1.5%, 2.0%, 5%, and 87% barium, and nickel-strontium alloys containing respectively about 0.8%, 40% and.78% strontium. 25 v Nickel alloys containing large amounts of barium and/or strontium are crystalline in appearance, appreciably malleable, and more stable in air than is pure barium.

Major fields of use for the alloys of the inven- 30 tion include deoxidizers for metals, pyrophoric alloys, and cathode material for thermionic devices. Useful alloys for these purposes include those containing from 0.75% to 99% barium.

I claim: 35 1. Process of making nickel alloys containing more than about 1 superheated melt.

2. Process of making nickel alloys containing more than about 1% alkaline earth metal of the comprises melting superheating the melt to approximately 1000 C., and adding nickel to the superheated melt.

3. Process of making nickel alloys containing metal, superheating 1000 C., and adding melt.

4. Process of making nickel alloys containing 55 substantial amounts up to 65% alkaline earth metal of the group consisting of barium and strontium, which comprises melting the alkaline earth metal, superheating the melt to approximately 1000 0., adding nickel to the superheated melt to form an alloy of nickel and alkaline earth metal containing about 5% to 35% nickel, and adding the alloy so formed to molten nickel.

5. An alloy consisting of nickel and barium, and containing more than about 65% of barium,

said alloy being produced by dissolving nickel in molten barium.

6. An alloy consisting of nickel and alkaline earth metal of the group consisting of barium and strontium and containing more than about 65% of alkaline earth metal, said alloy being metallurgically identical with an alloy of the same composition produced by dissolving nickel in moltenalkaline earth metal.

HUGH S. COOPER. 

